温度控制对薄规格带钢炉内跑偏的影响

连退炉生产0.5mm厚以下带钢时,炉内带钢跑偏除考虑来料板形、炉辊辊形及粗糙度、炉内带钢张力等因素外,加热段带钢升温速率也不可忽视。原因是炉子热容量大,热惯性大,温度检测和控制存在固有的滞后性,带钢升温速率不能得到有效控制,升温速率过快,使加热段带钢出现微瓢曲,在低张力控制下,带钢出现跑偏。通过采用较为精准的带钢温度PID调节器输出限幅控制方案,提高带钢温度控制精度,降低带钢升温速率,明显改善了薄规格带钢炉内跑偏问题。

Effect of temperature control on the strip deviation in annealing furnace

In addition to the billet shape,furnace roll shape and roughness,and strip tension,the strip reheating rate in heating zone of annealing furnace was a important factor to influence thinner than 0.5 mm strip running deviation in the furnace.The causes were that the furnace thermal capacity was big,the thermal inertia was high,the temperature detection and control had hysteretic nature.Because of the fast heating rate,the strip in heating zone buckled a little,so the strip was easy to deviate.By adopting the precise control scheme of strip temperature PID output limiting,upgrading the strip temperature accuracy,and decreasing the heating rate,the thin gauge strip deviation in the furnace was obviously improved.